RNAi is currently being tested as a therapeutic tool for genetic diseases and other conditions. Consider the following: cystic fibrosis caused by loss of function of the CFTR gene, HIV infection, and cancer caused by hyperactivity of a growth factor receptor. Which of these may be treatable by RNAi, and which not? Explain your reasoning.

Verified step by step guidance

1. span>Step 1: Understand the mechanism of RNA interference (RNAi). RNAi is a biological process where RNA molecules inhibit gene expression or translation, effectively silencing targeted genes. It is particularly useful for reducing the expression of genes that are overactive or harmful.</span
2. span>Step 2: Analyze cystic fibrosis. Cystic fibrosis is caused by a loss of function mutation in the CFTR gene. Since RNAi is used to silence gene expression, it would not be suitable for treating cystic fibrosis, as the condition is due to a lack of CFTR function, not an overexpression.</span
3. span>Step 3: Consider HIV infection. RNAi could potentially be used to target and silence viral genes necessary for HIV replication. This could help in reducing the viral load in infected individuals.</span
4. span>Step 4: Evaluate cancer caused by hyperactivity of a growth factor receptor. RNAi could be used to silence the overactive growth factor receptor gene, potentially reducing the proliferation of cancer cells.</span
5. span>Step 5: Conclude which conditions are treatable by RNAi. RNAi is suitable for conditions where gene silencing is beneficial, such as HIV infection and cancers caused by overactive genes, but not for conditions like cystic fibrosis, which require gene function restoration.</span

Key Concepts

RNA Interference (RNAi)

RNA interference (RNAi) is a biological process in which RNA molecules inhibit gene expression or translation, effectively silencing specific genes. This mechanism can be harnessed therapeutically to target and degrade mRNA from genes that are overactive or mutated, making it a promising approach for treating genetic diseases and conditions like cancer and viral infections.

Gene Function and Loss of Function Mutations

Gene function refers to the specific role a gene plays in the body, including the production of proteins necessary for normal cellular processes. Loss of function mutations, such as those in the CFTR gene causing cystic fibrosis, result in the absence or malfunction of these proteins, which can be challenging to treat with RNAi since the underlying issue is not merely the presence of faulty mRNA but the lack of functional protein.

Targeting Oncogenes and Viral Genes

Oncogenes are genes that, when mutated or overexpressed, can lead to cancer by promoting uncontrolled cell growth. RNAi can effectively target these oncogenes or viral genes, such as those involved in HIV infection, by degrading their mRNA, thereby reducing the expression of harmful proteins and potentially reversing disease progression.